Prefer require_relative to avoid calculating relative paths

lib/generators/rspec/install/templates/spec/rails_helper.rb

@@ -1,7 +1,7 @@
 # This file is copied to spec/ when you run 'rails generate rspec:install'
 require 'spec_helper'
 ENV['RAILS_ENV'] ||= 'test'
-require File.expand_path('../config/environment', __dir__)
+require_relative '../config/environment'
 # Prevent database truncation if the environment is production
 abort("The Rails environment is running in production mode!") if Rails.env.production?
 require 'rspec/rails'

spec/generators/rspec/install/install_generator_spec.rb

@@ -19,6 +19,10 @@ def maintain_test_schema
     match(/ActiveRecord::Migration\.maintain_test_schema!/m)
   end
 
+  def require_rails_environment
+    match(/^require_relative '\.\.\/config\/environment'$/m)
+  end
+
   def require_rspec_rails
     match(/^require 'rspec\/rails'$/m)
   end
@@ -62,6 +66,11 @@ def filter_rails_from_backtrace
   end
 
   context "generates spec/rails_helper.rb" do
+    specify "requiring Rails environment" do
+      run_generator
+      expect(rails_helper).to require_rails_environment
+    end
+
     specify "requiring rspec/rails" do
       run_generator
       expect(rails_helper).to require_rspec_rails
@@ -99,6 +108,11 @@ def filter_rails_from_backtrace
       hide_const("ActiveRecord")
     end
 
+    specify "requiring Rails environment" do
+      run_generator
+      expect(rails_helper).to require_rails_environment
+    end
+
     specify "requiring rspec/rails" do
       run_generator
       expect(rails_helper).to require_rspec_rails